| Because water quality parameters do not well reflect the ecological condition of rivers, scientists rely on ecosystem evaluation systems. The literature indicates two primary methods in current use for evaluating aquatic ecological conditions in China; a multi-index evaluation method, based on water quality and biological indicators, and the fuzzy analytic hierarchy process (FAHP), based on water quantity, quality, aquatic life, riparian zone condition and river morphology. In order to understand the ecological condition of the rivers in Liaoning province, five evaluation indices were used that included the hydrology, water quality, river morphology, biological condition and the social environment. The ecological condition of 12 primary rivers in Liaoning Province, distributed across the Province, was evaluated using a fuzzy comprehensive assessment model. The construction of the model was based on water quality monitoring data for each river from 2012, analysis of long term hydrological data (1956-2010) and evaluation of water ecological status using fuzzy mathematics. Evaluation results indicate the following water ecological conditions: The downstream sections of the Hunjiang, Pushihe, Aihe and Dayanghe rivers are excellent; the upstream section of the Taizihe River is good; the Qinghe, Xiaolinghe and Lieguhe rivers are moderate; the main stems of the Liaohe, Raoyanghe and Hunhe rivers and the downstream sections of Taizihe and Dalinghe Rivers are poor. The main factors affecting the ecological conditions of the rivers include longitudinal connectivity, degree of water resource development and utilization, base flow and water qualification rate. Based on the results, the following countermeasures and engineering measures are recommended: 1) Control point source and non-point source pollution, limit total pollution loads to rivers and strengthen management of the water catchment area; 2) improve connectivity of the upstream and downstream sections; 3) operate the dam and water storage projects on the rivers so as to maintain an adequate base flow; 4) implement strict water management. This study provides scientific evidence to support conservation of water resource in Liaoning Province.
|
